Do you have 18 segments or do you only have one? If you have only have one segment then the timer will stop after the first loading screen. Make sure to download the splits from the resource page https://www.speedrun.com/resourceasset/bx1fa (link to splits).

Your placement on the leaderboard is so low because you weren't compairing against game time. You were using real time so you got placed below everyone who used game time. Just right click livesplit -> compare against -> game time for your next run then you should be fine.